For accountants
Every practice is being urged to adopt AI. For an accountant that advice has a catch, because the cloud tools send confidential client financials to servers you do not control. Arsenale is the alternative: a small computer that runs capable AI entirely in your office. No cloud, no subscription, owned outright.
Most practices cannot safely use the AI everyone is talking about. Client confidentiality and data-protection duties make sending a client's books and bank data to a cloud service a real problem.
Arsenale removes the problem by removing the cloud. The AI runs on a small computer in your office. Client ledgers, bank data, returns and correspondence stay on the device. There is no monthly fee and no metering.
It already does bookkeeping and accounts preparation grounded strictly in the client's own figures, tracks every filing deadline, and, most importantly, tells you when the numbers do not reconcile rather than papering over the gap.
Practical, on-the-machine work, with you reviewing and signing off.
Imports bank statements, categorises transactions, reconciles, and self-checks. It flags what does not tie out rather than forcing a balance.
Drafts management accounts, the profit and loss and the balance sheet strictly from the client's own ledgers, with a provenance trace for every figure.
Tracks Corporation Tax, Self Assessment, VAT and PAYE deadlines for each client, and drafts computations from the client's own figures.
Prepares MTD-ready VAT returns and keeps the digital records the rules require. Direct submission to HMRC arrives with recognition, which is in progress.
Surfaces the entries worth a second look: the duplicates, the misposts, the figures that do not sit right.
Drafts the chase emails, the missing-information requests and the year-end letters, for you to review and send.
Give it a set of books with a gap, and it will tell you it cannot reconcile rather than inventing a figure to make it balance. For work where a wrong number is a real liability, that single behaviour is the difference between a tool you can rely on and one you cannot. It is grounded strictly in the client's own ledgers and filed documents, and it does not guess.
It is the first thing we will show you in a demo. Give it books with something missing, and watch it decline to invent the number.
An honest, head-to-head look at working a client's books on Arsenale versus a cloud AI assistant.
| Arsenale | A cloud AI assistant | |
|---|---|---|
| Where client financials live | On the device, in your office. They never leave. | On the provider's servers, often overseas. |
| Confidentiality and data protection | Client data stays in the building. | Confidential financials sent to a third party. |
| Who signs off the work | The accountant. It drafts, you approve. | Varies, and easy to over-rely on. |
| If the numbers do not reconcile | It says so, and stops, rather than inventing one. | It will often produce a confident, wrong figure. |
| Cost | One-off purchase, owned outright. Optional support licence. | Subscription, metered, trending up. |
| If the vendor changes or leaves | It keeps working. No cloud dependency, no kill switch. | You renegotiate or lose access. |
Two things are in development. First, Making Tax Digital recognition, so the appliance can submit VAT and Income Tax returns to HMRC directly. We are pursuing HMRC recognition now; until then the system prepares MTD-ready returns for you to file. Second, the agent preparing the return and the associated payment for you to authorise, through regulated payment partners. You authorise every submission and every payment. The AI never files or moves money on its own. Both arrive as managed updates, with the same review-and-approve gate as everything else the system does.
That is the point of it. Because the AI runs on a device you own, in your office, client books and bank data never leave the building. You review and sign off the work, and nothing is submitted without a person authorising it.
It is built not to. When the books do not reconcile, it tells you rather than forcing a balance. It is grounded strictly in the client's own ledgers, and we will demonstrate this directly.
We are working towards HMRC recognition for Making Tax Digital. Today the system prepares MTD-ready VAT returns and keeps the digital records the rules require. Direct submission to HMRC arrives with recognition, which is in progress.
No. It drafts and prepares; you review, approve and file. Filing and payments, when those features arrive, are prepared for your authorisation through regulated partners and HMRC's service, and are never done by the AI alone.
£2,499 one-off, owned outright, with no per-use metering. An optional annual licence covers ongoing model and software updates. See the pricing page for detail.
The appliance keeps working. There is no cloud back-channel and no kill switch. What you have paid for remains yours and remains functional.
No. It arrives configured. Switch it on and use it. There is no command line and no setup project.
Yes. In a demo we can load one of your own clients' books on the device, and you will see it worked through without anything leaving the room.
A demo takes about fifteen minutes, in person, with no obligation. Bring a set of books and watch it run on the device, with nothing leaving the room.
More on how the platform keeps data in the building: the trust page.